🔧 Altima - Timing Belt Replacement

Your Altima with the 3.5L V6 does not use a timing belt. It uses an internal timing chain, which is designed to last much longer and is not a normal maintenance replacement item like a rubber timing belt.

If you are hearing rattling on startup, have cam/crank correlation codes, or suspect timing chain stretch, this becomes a major engine timing-chain service.

Difficulty Level: Advanced | Estimated Time: 10-16 hours

---

⚠️ Safety & Precautions

• ⚠️ This is an advanced repair that can cause severe engine damage if cam timing is set incorrectly.
• ⚠️ Support the engine securely before removing the right-side engine mount.
• ⚠️ Disconnect the negative battery cable before working near the starter, alternator wiring, or engine harness connectors.
• ⚠️ Let the engine cool completely before draining coolant or removing cooling-system parts.
• ⚠️ The timing chain is inside the engine front cover, so engine oil and coolant contamination must be avoided.
• ⚠️ Do not rotate the crankshaft or camshafts independently after the chains are removed.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Metric socket set 8mm-22mm
• Metric wrench set 8mm-19mm
• 3/8-inch drive ratchet
• 1/2-inch drive breaker bar
• 1/2-inch drive torque wrench
• 3/8-inch drive torque wrench
• Crankshaft pulley holding tool (specialty)
• Harmonic balancer puller (specialty)
• Engine support bar (specialty)
• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• Trim clip removal tool
• Flat-blade screwdriver
• Phillips screwdriver
• Pry bar 12-inch
• Gasket scraper plastic
• Brake cleaner aerosol
• Drain pan 10-quart
• Coolant funnel spill-free
• Shop towels
• Paint marker
• Safety glasses
• Nitrile gloves

A harmonic balancer puller is a tool that safely removes the crankshaft pulley without prying against the engine. An engine support bar holds the engine from above while an engine mount is removed.

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Primary timing chain - Qty: 1
• Secondary timing chains - Qty: 2
• Timing chain tensioners - Qty: 3
• Timing chain guides - Qty: 1 set
• Front timing cover sealant - Qty: 1
• Crankshaft front oil seal - Qty: 1
• Valve cover gaskets - Qty: 2
• Intake plenum gasket set - Qty: 1
• Engine oil - Qty: 5 quarts
• Oil filter - Qty: 1
• Nissan-compatible blue coolant - Qty: As needed
• Accessory drive belt - Qty: 1

---

📋 Before You Begin

• Park your Altima on level ground and set the parking brake.
• Place wheel chocks behind the rear wheels.
• Open the hood and let the engine cool fully.
• Use a 10mm socket to disconnect the negative battery cable.
• Raise the front of the car with a floor jack and support it with jack stands.
• Remove the right-front wheel and inner splash shield for access.
• Take photos before removing hoses, brackets, and connectors. This helps during reassembly.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm This Is a Timing Chain Job

• Your Altima does not have a replaceable timing belt.
• If you are doing routine maintenance only, do not replace the timing chain unless there is a verified problem.
• Common signs include cold-start chain rattle, timing-related fault codes, rough running, or metal debris in oil.
• Do not replace it preventively.

Step 2: Disconnect Battery and Raise Vehicle

• Use a 10mm socket to loosen the negative battery terminal.
• Move the cable aside so it cannot touch the battery post.
• Use a floor jack to lift the front of the vehicle.
• Place jack stands under approved front support points before working underneath.

Step 3: Remove Right-Front Wheel and Splash Shield

• Use a 21mm socket to remove the right-front wheel lug nuts.
• Remove the wheel and set it aside.
• Use a trim clip removal tool and Phillips screwdriver to remove the right inner fender splash shield.
• This gives access to the crankshaft pulley and front engine cover area.

Step 4: Drain Engine Oil and Coolant

• Place a 10-quart drain pan under the engine.
• Use a 14mm socket to remove the engine oil drain plug.
• Drain the oil fully, then reinstall the drain plug.
• Torque to 34 Nm (25 ft-lbs)
• Drain coolant from the radiator drain into a clean drain pan.
• Use nitrile gloves and safety glasses because coolant is slippery and toxic.

Step 5: Remove Engine Covers and Intake Components

• Use a 10mm socket to remove the plastic engine cover fasteners.
• Use a flat-blade screwdriver to loosen the intake duct clamps.
• Disconnect the mass air flow sensor connector by pressing the release tab.
• Remove the air intake duct and air cleaner outlet tube.
• Use a 10mm socket and 12mm socket to remove brackets blocking access to the upper intake plenum.

Step 6: Remove Upper Intake Plenum

• Label vacuum hoses and connectors with a paint marker.
• Use a 10mm socket to remove the upper intake plenum bolts.
• Lift the plenum carefully and remove the old gasket.
• Cover open intake ports with clean shop towels.
• Nothing can fall inside.

Step 7: Remove Accessory Drive Belt

• Use a wrench on the belt tensioner to relieve belt tension.
• Slide the accessory drive belt off the pulleys.
• Inspect belt routing before removal or take a photo.
• A tensioner is a spring-loaded pulley that keeps the belt tight.

Step 8: Support Engine and Remove Right Engine Mount

• Install the engine support bar across the upper strut area.
• Attach the support hook to a safe engine lifting point.
• Apply light upward tension only.
• Use a 14mm and 17mm socket to remove the right-side engine mount fasteners.
• Remove the mount from the vehicle.
• Do not place your hand between the mount and body while removing it.

Step 9: Remove Crankshaft Pulley

• Use the crankshaft pulley holding tool to keep the pulley from turning.
• Use a 1/2-inch breaker bar and correct-size socket to loosen the crankshaft pulley bolt.
• Use a harmonic balancer puller to remove the pulley from the crankshaft.
• Do not pry against the aluminum timing cover.

Step 10: Remove Valve Covers

• Use a 10mm socket to remove ignition coil fasteners.
• Disconnect ignition coil connectors and remove the coils.
• Use a 10mm socket to remove both valve cover bolts.
• Lift off the valve covers and remove the old gaskets.
• Keep dirt out of the exposed cylinder heads.

Step 11: Remove Front Timing Cover

• Use 10mm, 12mm, and 14mm sockets to remove timing cover bolts.
• Note bolt locations because lengths vary.
• Use a plastic gasket scraper to gently separate the cover.
• Do not gouge the aluminum sealing surfaces.
• Remove the front cover and set it on a clean surface.

Step 12: Set Engine to Top Dead Center

• Use a socket and breaker bar on the crankshaft bolt to rotate the engine clockwise only.
• Align the crankshaft and camshaft timing marks according to the timing marks on the chain system.
• Top Dead Center means cylinder number 1 is at the top of its compression stroke.
• Use a paint marker to mark the old chain and sprocket positions before removal.

Step 13: Remove Timing Chain Tensioners and Guides

• Use a 10mm socket to remove the timing chain tensioners.
• Use a 10mm and 12mm socket to remove the chain guides.
• Remove the primary timing chain first.
• Remove the secondary timing chains after confirming camshaft positions are marked.
• Do not rotate camshafts after chains are removed.

Step 14: Install New Secondary Timing Chains

• Match the colored chain links to the camshaft sprocket timing marks.
• Use the paint marker marks as an extra visual check.
• Install new secondary chain guides with a 10mm socket.
• Install new secondary tensioners but do not release the tensioner pins until the chains are fully seated.

Step 15: Install New Primary Timing Chain

• Align the colored chain links with the crankshaft sprocket and camshaft idler sprocket timing marks.
• Install the new primary chain guides using a 10mm and 12mm socket.
• Install the new primary chain tensioner using a 10mm socket.
• Release the tensioner retaining pins only after all marks are aligned.
• Check timing marks twice.

Step 16: Rotate Engine by Hand

• Use a breaker bar and socket on the crankshaft bolt.
• Rotate the engine clockwise two full revolutions by hand.
• Stop immediately if the engine locks or feels like it hits something solid.
• Recheck timing mark alignment after rotation.
• This confirms valves and pistons are not contacting.

Step 17: Clean and Seal Front Timing Cover

• Use a plastic gasket scraper to clean the timing cover and engine sealing surfaces.
• Use brake cleaner aerosol and shop towels to remove oil from sealing surfaces.
• Install a new crankshaft front oil seal into the cover.
• Apply front cover sealant in the correct bead pattern around oil and coolant passages.
• Install the timing cover before the sealant skins over.

Step 18: Reinstall Front Timing Cover

• Carefully position the front timing cover onto the engine.
• Start all bolts by hand to avoid cross-threading.
• Use 10mm, 12mm, and 14mm sockets to snug bolts in stages.
• Torque fasteners to Nissan service specification by bolt size and location.
• If exact bolt-location torque data is not available, do not guess; use the OEM torque chart.

Step 19: Reinstall Valve Covers

• Install new valve cover gaskets into the valve covers.
• Place the covers onto the cylinder heads.
• Use a 10mm socket to install valve cover bolts evenly.
• Torque to 8.3 Nm (73 in-lbs)
• Reinstall ignition coils with a 10mm socket.

Step 20: Reinstall Crankshaft Pulley

• Slide the crankshaft pulley onto the crankshaft snout.
• Use the crankshaft pulley holding tool to hold the pulley.
• Install the crankshaft pulley bolt with a socket and torque wrench.
• Use the Nissan service torque-plus-angle procedure for the crankshaft pulley bolt.
• Do not use an impact wrench for final tightening.

Step 21: Reinstall Engine Mount and Accessory Belt

• Use a 14mm and 17mm socket to reinstall the right engine mount.
• Tighten mount fasteners to Nissan service specification.
• Remove the engine support bar only after the mount is fully tightened.
• Use a wrench on the belt tensioner to install the accessory drive belt.
• Confirm the belt ribs sit correctly in every pulley groove.

Step 22: Reinstall Intake Plenum and Intake Duct

• Remove shop towels from the intake ports.
• Install new intake plenum gaskets.
• Use a 10mm socket to reinstall the upper intake plenum bolts.
• Torque to 25 Nm (18 ft-lbs)
• Reconnect vacuum hoses and electrical connectors.
• Use a flat-blade screwdriver to tighten intake duct clamps.

Step 23: Refill Oil and Coolant

• Install a new oil filter by hand until the gasket contacts, then tighten 3/4 turn more.
• Add the correct amount of fresh engine oil.
• Use a spill-free coolant funnel to refill the cooling system with Nissan-compatible blue coolant.
• Reconnect the negative battery cable using a 10mm socket.

Step 24: Start and Check

• Start the engine and let it idle.
• Watch the oil pressure warning light. Shut off immediately if it stays on.
• Check for oil leaks around the front cover and valve covers.
• Check for coolant leaks around hoses and the front cover area.
• Let the engine reach operating temperature and top off coolant as needed.

---

✅ After Repair

• Check engine oil level after the first full warm-up and again after the first short drive.
• Check coolant level after the engine cools completely.
• Listen for chain rattle, ticking, or abnormal scraping noises.
• Scan for diagnostic trouble codes if the check engine light comes on.
• Recheck for leaks after 50-100 miles.
• If idle is unstable after plenum removal, an idle air volume relearn may be needed with a compatible scan tool.

---

💰 DIY vs Shop Cost

Shop Cost: $2,200-$3,800 (parts + labor)

DIY Cost: $450-$900 (parts only)

You Save: $1,750-$2,900 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 10-14 hours.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.